The inventive concept relates to a phosphor and an electronic device including the phosphor, and more particularly, to a yellow phosphor emitting light by using a blue light as an excitation source and a light-emitting device including the yellow phosphor.
Lighting using light-emitting diodes (LEDs) presents several advantages, such as energy saving, long lifespan, and the like. As a result, LED-based lighting is gaining widespread use in a variety of different fields, such as lamps for street lights or cars.
A combination of an LED and a yellow phosphor is generally used for providing lighting using LEDs. The yellow phosphor emits yellow light by using light emitted from the LED as an excitation source. A desired lighting color is generated by mixing yellow derived from the yellow phosphor and a color of light emitted from the LED. For example, when a blue LED and a yellow phosphor are combined with each other, blue and yellow which complement each other are mixed, and thus, pseudo-white light is obtained.
Examples of the yellow phosphor that is used in combination with the blue LED include a sialon-based phosphor or an yttrium aluminum garnet-based phosphor (Y, Gd)3(Al, Ga)5O12:Ce (i.e., YAG:Ce-based phosphor) activated with cerium (Ce) (refer to Patent reference 1). Optical characteristics of the yellow phosphor, such as a light-emitting spectrum distribution and the like, are satisfactory. Particularly, the YAG:Ce-based phosphor is excellent in that pseudo-white light having a color rendering property is obtained therefrom. Examples of prior arts related to the phosphor according to the inventive concept include Patent references 2 through 6.
Furthermore, a phosphor (a representative example: La4−αCaαSi12O3+αN18−α:Eu) that is represented by a general formula (Ca1−x, M1)a(La1−y, M2y)bSicNdOe (where 1≦a≦30, 0.3a≦b≦1.7a, 1.5(a+b)≦c≦3(a+b), 1.2c≦d≦1.5c, 0.8(a+1.5b)≦e≦1.2(a+1.5b), 0≦x≦0.5, 0≦y≦0.5, M1 is at least one selected from Ba, Mg, Sr, Mn, and Zn, and M2 is at least one selected from Y, Lu, Sc, Gd, Tb, and Ce) has been reported (refer to References 7 and 8).